This invention relates to bronchoscopy and is more particularly concerned with a ventilation system for use with a viewing bronchoscope.
A bronchoscope comprises a tubular instrument which can be inserted down a patient's trachea to permit viewing of the bronchi and to aid in the performance of certain bronchial surgical procedures. It is common practice to use an open-ended bronchoscope tube and to ventilate the patient during bronchoscopy by means of a short venturi needle located at the open proximal end of the tube, often attached to the rim of the opening. A high pressure gas stream (oxygen) is directed down the tube from the venturi needle and this entrains a large volume of air which is drawn through the open proximal end thereby ensuring adequate ventilation.
However, it is now known to mount a laser manipulator at the proximal end of the bronchoscope tube and, with this arrangement, the problem arises that inflow of entrained air is blocked and thereby ventilation is reduced. Also, on use of the laser manipulator, smoke is generated and this becomes deposited in the patient's lungs if ventilation is effected during application of the laser. In the latter respect, it is known to use a bronchoscope having a separate suction channel for evacuation of smoke but there is the problem of synchronising ventilation and suction with smoke generation.